This invention relates to means of coupling a rotating output shaft of a motor or actuating device to a rotating valve stem used in butterfly valves, ball valves, plug valves, or other rotary devices.
Couplings heretofore used for this purpose are milled or precision formed out of solid metal to conform within very close tolerances to a given set of motor shaft dimensions on one end and a specific shaft dimension on the other (valve) end. Such a procedure is very expensive and inflexible, since there exists a wide disparity between shaft dimensions of various valve sizes. A given actuator size might be used for butterfly valve sizes 2", 3" and 4". Each of these different butterfly valves, as a rule, has a different shaft dimension and would, therefore, require three separate solid couplings. If the same actuator were to be used also for a variety of ball valves or other valve types, then the required number of couplings will increase in proportion with the accompanying loss of flexibility and the need for stocking a great variety of coupling parts for each actuator.
My invention overcomes these disadvantages by providing for the use of only one single coupling configuration per actuator size. My invented coupling has the capability of adjusting either in elastic or in the plastic deformation range to a great variety of valve shaft dimensions.
A further object of my invention is to provide for a coupling that is inexpensive and which can be made by a simple stamping process without the need for costly machining operations.
Yet, a third object of my invention is the provision of a coupling that easily tolerates a misalignment between the two separate shaft ends without impairing the load carrying torque transmitting capabilities.
In view of these and other advantages, my invention can be more plainly understood in view of the accompanying drawings.